Grinding machine for brake drums for wheels



May 11, 1965 sHlGEKlcl-n MIYABAYAsHl 3,182,427

GRINDING MACHINE FOR BRAKE DRUMS FOR WHEELS Filed oct. s, 1962 for/laysUnited States Patent 3,182,427 GRINDING MACHINE FOR BRAKE DRUMS FORWHEELS Shigekich Miyabayashi, Chigusa-ku, Nagoya-shi, Aichiken, Japan,assignor to The Nippon Tolri Kaisha Ltd., Nagoya-shi, Aichi-ken, Japan,a corporation of Japan Filed Oct. 8, i1962, Ser. No. 229,069 Claimspriority, application Japan, Oct. 26, 1961, 36 38 832 The presentinvention relates to a grinding machine for performing grindingoperation according to the condition of the peripheral surface of abrake drum for wheels which is iixed on a drum grinding device, and ischaracterized in that an automatic feeding device utilizing a cammechanism is provided in the bed of the grinding machine for advancing agrinder wheel so that the grinder Wheel will be slowly advanced ingrinding operation to perform automatically desired amount of cutting onthe peripheral surface of a brake drum.

The present invention will ybe explained concretely with reference toone of the embodiments off the present invention illustrated in theaccompanying drawings, in which:

FIG. l is a side view, partly in section, of an apparatus of the presentinvention, showing essential parts thereof; and

FIG. 2 is a rear view partly in section, of same on a greater scale,showing only a part of the apparatus.

A shaft 2 is horizontally and rotatably mounted on the side wall in abed 1 and a worm wheel 3 and a grooved cam 4 are keyed on said shaft,the cam being positioned to the right of the Worm wheel. Another sha-ft7 provided with a worm 5 which engages the lower end of the worm wheel 3is rotatably mounted on the side wall in the bed 1. The shaft 7 has apulley 6 fixed on its one end and it is so designed that rotation may betransmitted to the grooved cam 4 through the pulley 6, the worm 5 Iandthe wo-rm wheel 3 by a motor Ma placed on the bottom in the bed 1. Inthis case, the pulley 6, the Worm 5 and the worm wheel 3 are designed tornake the rotation speed of the grooved cam 4 very low.

In the center of the recess 8 on the top of the bed 1 is fixed a cradle9 having a guiding surface of dove-tail groove shape, into which asliding member 11 provided with a screw hole 10 at its center is mountedslidably in the direction of front and back. On the central part of thelower surface of said sliding member 11 is iixed a rotatable guiderol-ler 12 which passes through the top surface of the bed 1 downwardlyand vertically and enters the groove of the cam 4. Accordingly thesliding member 11 slides to front and back according to the rotation ofthe cam 4. On the guiding surface of the bed 1 is mounted a column 13which is slidable to f-ront and back. A feed screw provided with 4a feedhandle 14 lfor feeding to front and back is rotatably mounted inhorizontal position by a bearing on the rear lower part of the column13. The feed screw 15 is inserted into the screw hole 10 of the slidingmember 11 and the position of a grinder wheel 16 may be adjusted byscrewing the feed screw 15 into the screw hole 10 by the feed handle 14,when the grinder wheel is worn. To the front olf the column 13 isattached a stand 17 which has a grinder wheel 16 and supports on itsupper surface a motor Mb for rotating said grinder wheel. This stand canbe moved up and down by means of a feed handle 18 for vertical ymotionwhich is mounted in the rear of the column 13.

In the operation of the present invention, the height of the grinderwheel 16 is adjusted by the operation of the handle 18 for verticalfeeding to bring the grinder wheel near the surface of a brake drum D tobe worked which comes from the back in a flow on a conveyor (not shown)and is rotating being horizontally fixed on a drum grinding device G.The cam 4 is rotated at greatly reduced speed, by the motor Ma in thebed 1 through the pulley 6, the worm 5 and the worm wheel 3 as describedbefore. Accordingly the guide roller 12 attached to the lower surface ofthe sliding member 11 shifts the sliding member slowly to front by therotation of the grooved cam 4. The column 13 connected with the slidingmember 11 by the feed screw 15 is moved forwardly by the advancement ofthe sliding member together with the grinder wheel 16 attached to thefront surface of the column. Thus the grinder wheel 16 is automaticallyadvanced to perform cutting operation while the brake drum D is rotated.When the grooved cam 4 rotates to pass the upper dead point, the motionof the sliding member 11 and consequently that of the grinder wheel 16is reversed to iinish the cutting operation. By adjusting the upper deadpoint of the grooved cam 4 to required amount of cutting of the brakedrum, the required amount of cutting can be automatically attained byone operation. When the grinder wheel 16 has worn and its diameter hasbecome small, the adjustment can be carried out by advancing the column13 by operating the feed handle 14 for advancement.

In the present invention, the required amount of cutting of theperipheral surface of a brake drum attached on a drum grinding device Gcan be automatically attained by the use of a cam mechanism. Accordinglyit makes it possible to perform the cutting operation of brake drums forwheels which requires mass production by a continuous How operation. Iteliminates the risks of the operators which are involved in the case ofoperation of grinding of individual pieces as before. Furthermore itbrings about saving in time and labour. Thus the advantage of thepresent invention is very great.

I claim:

l. A grinding machine for brake drums for wheels comprising a column onwhich a grinder wheel and a motor for driving said grinder wheel areattached slidably in a vertical direction, a bed having an upper surfaceand supporting said column and said column being reciprocably slidablein a horizontal direction on said upper surface, a sliding membermounted on the bed, a feed screw rotatably mounted in a lower part ofthe column and extending in a horizontal direction and screwed into ascrew hole provided in said sliding member, a grooved circular camrotatably mounted below the sliding member, and a guide roller providedat the bottom of the sliding member and inserted into a groove of saidcam.

2. An apparatus for grinding a brake drum comprising a column, agrinding wheel secured to said column, a brake drum support, a housing,the top of which is formed as a grinding bed and supports said columnslidably in a horizontal direction, a shaft mounted in the housingsubstantially parallel to the said horizontal direction, means forrotating said shaft; a cam wheel keyed on said shaft and having aperipheral, endless groove with outlines extending obliquely to themajor axis of said shaft; a pin with a guide roller inserted into saidgroove, said pin being mounted at the bottom of said column and passingthrough an opening at the top of said housing; a sliding member mountedon the housing and connected with said pin, said sliding member having athread; a feed screw rotatably mounted lat the bottom of said column andengaging with said thread; the cam wheel during rotation by the drivingmeans moving the grinding wheel towards and away from the brake drumsupport and the feed screw being adapted to adjust the distance betweenthe grinding wheel and the brake drum support.

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(References on following page) 3 f 4 Y Reim-ences Cited by the ExaminerFOREIGN PATENTS UNITED STATES PATENTS Y 448,191 8/27 Germany. 1,952,1303/34 Harrison et al.

2,325,701 8/43 Murray 51-166 2,384,512 9/ 45 Wiken et a1. 5 I.SPENCEROVERHOLSER, Examiner.

LESTER M. SWINGLE, Primary Examiner.

1. A GRINDING MACHINE FOR BRAKE DRUMS FOR WHEELS COMPRISING A COLUMN ONWHICH A GRINDER WHEEL AND A MOTOR FOR DRIVING SAID GRINDER WHEEL AREATTACHED SLIDABLY IN A VERTICAL DIRECTION, A BED HAVING AN UPPER SURFACEAND SUPPORTING SAID COLUMN AND SAID COLUMN BEING RECIPROCABLY SLIDABLEIN A HORZIZONTAL DIRECTION ON SAID UPPER SURFACE, A SLIDING MEMBERMOUNTED ON THE BED, A FEED SCREW ROTATABLY MOUNTED IN A LOWER PART OFTHE COLUMN AND EXTENDING IN A HORIZONTAL DIRECTION AND SCREWED INTO ASCREW HOLE PROVIDED IN SAID SLIDING MEMBER, A GROOVED CIRCULAR CAMROTATABLY MOUNTED BELOW THE SLIDING MEMBER, AND A GUIDE ROLLER PROVIDEDAT THE BOTTOM OF THE SLIDING MEMBER AND INSERTED INTO A GROOVE OF SAIDCAM.